1. Field of the Invention
The present invention relates to a measurement device for communication that measures the quality of communication in communication equipment such as a PBX (private branch exchange) that makes up a communication system via communication lines (including telephone lines).
2. Description of the Related Art
Measurement devices for communication have conventionally been manufactured for each specific type of measurement function. Examples of measurement devices for communication include the bit error meter shown in FIG. 1(a) in which bit error test function board 400a and interface function board 400b are interconnected; and a protocol analyzer such as shown in FIG. 1(b) in which protocol test function board 500a and interface function board 500b are interconnected; and these measurement devices are each used according to the tested item. Consequently, when a plurality of different test items such as bit error testing or protocol testing were to be measured, bit error meters and protocol analyzers were individually provided to conduct each respective test. Here, "interface function" refers to the function of converting to various types of communication interfaces, and "measurement function" refers to functions used in actual measurement such as bit error testing and protocol testing.
As described hereinabove, conducting communication tests on a communication device generally requires a plurality of measurement functions. In digital lines (such as ISDN lines), signaling channels exist independent of data channels (such as a channel for voice), and the test functions employed also differ accordingly. For example, a protocol testing function is employed for controlling calls in a signaling channel, and a bit error testing function is employed that can confirm the connection state in a data channel. As a result, judging the quality of one communication device has necessitated the provision of a plurality of communication measurement devices such as a bit error meters and protocol analyzers. For example, conducting communication tests on a PBX necessitated the connection of a plurality of measurement devices to PBX 600 as shown in FIG. 2. This figure shows a case in which bit error test function 602a and protocol test function 603a are connected by way of interface 601a, and in addition, bit error test function 602b and protocol test function 603b are connected by way of interface 601b.
As described hereinabove, because a prior-art measurement device for communication purposes had only one test function, measurement devices such as bit error meters and protocol analyzers had to be provided for each type of test item, and this necessity placed a great burden on the user. In addition, prior-art communication measurement devices did not allow compound testing by which, for example, a data channel could be correctly controlled by the signaling channel in a case in which a signaling channel and a data channel exist separately in one interface through time division multiplexing such as in an ISDN line.
In addition, although new applications and formats are constantly being developed in the field of communications, prior-art measurement devices for communication purposes have not allowed for the addition of measurement functions for new applications and formats, and as result, there has been a need for the development of a measurement device that can accommodate additional functions.